Liquid fuel supply pump for internal combustion engines



Nova. 17, 1931. J. c. SNODGRASS 1,832,539

LIQUID FUEL SUPPLY PUMP FOR INTERNAL COMBUSTION ENGINES Filed Sept. 3, 1929 2 Sheets-Sheet l man as mwr.

OIL FROM OIL LINE 7 Imbent r 3931- J. c sNoDGRAss LIQUID FUEL SUPPLY PUMP FOR INTERNAL COMBUSTION ENGINES 5, 192E 2 Sheets-Sheet Filed Sept.

w-lmwmu Patented Nov. 17, 1931 UNITED STATES PATENT 4 OFFICE JOSEPH O. SNODGRASS, OI NASHVILLE, TENN ESSEE, ASSIGNOB OF THREE-EIGHTHS TO BEVERLY Br MCKINNIE .AN'D TWO-EIGHTHS TO OHAUNCEY G. FOSTER, BOTH OF NASHVILLE, TENNESSEE LIQUID FUEL SUPPLY PUMP FOR INTERNAL COMBUSTION ENGINES Application filed September 3, 1929. Serial No. 390,138.

My invention has for one of its objects to provide a fluid pressure feed supply of fuel to an internal combustion engine of an airplane, automobile, or other motor driven body, and more particularly and primarily a pump operated from or by the oil in a pressure lubricated motor system. It has as a further object to provide a-pump operated from or by the oil of a pressure lubricated motor system and associated parts for supplying the fuel under pressure to the engine and in which the fuel will not be fed to the engine when the oil supply fails and thereby insuring safety by warning that the oil supply is exhausted.

It has for a further object an elastic or expansible air chamber in communication with the fuel supply line and in which air 1s trapped to supply pressure to the fuel in the intervals between the strokes of the pump. It has also for its object to provide a spring associated with the motor piston, which may be of the diaphragm type, to assist in restoring the piston to normal position between its strokes; also to provide a fuel feed pump requiring no packings or stufli ng boxes.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, the invention consists in the features hereinafter described and then sought to be clearly defined by the claims, reference being had to the accom anying drawings forming a part hereof, an in which Figure 1 is a side elevation of thefuel feed Figure 2 1s a front elevation;

Figure 3 is a vertical section through Figure 1;

Figure 4 is aplan view on line 4-4 of Figure 3;

igure 5 is a section through the lower or oil receiving diaphragm chamber of the pump, with its parts in osition when the in- I flow of oil is cut-off an oil exhaust open;

Figure 6 is a horizontal section, enlarged, through the valveoperating lever of the mo} tor cylinderor chamber. 1 I

In the drawings, there is illustrated the preferred embodiment-of the invention and which comprises a chamber 1, designated for .17 and convenience a motor chamber, and from which a pumping chamber 2 is operated for furnishing a supply of liquid fuel, for instance gasoline, under pressure to an internal combustion engine (not illustrated) of an airplane, automobile or other motor driven body or Vehicle. This improved fuel feed pump will be connected with the oil feed line of an automobile or other motor driven body, for instance at an appropriate point in the oil line between the oil pump and oil indicator gauge on the dash or instrument board so that oil will be conducted from the oil feed line through a pipe 3 leading to the motor chamber from which the fuel feed pump of the present invention will be actuated by the pressure of the oil received from the oil line of the pump which feeds oil to parts to be lubricated, and whereby the pressure of the oil pumped through the oil line will be utilized for feeding liquid fuel, for'instance gasoline, to an internal combustion engine.

The motor chamber 1 has a pulsating fluid pressure actuated diaphragm 4 of suitable material reinforced by a late 5 and clamped to the body of the chamfier by a ring 6 and threaded bolts 7. The diaphragm is connected by nuts 8 and 9 and washer 10, to a slidable stem ll passing through the chamber 1 and having its lower enlarged or headed end provided with a flexible pulsating diaphragm 17 of suitable material, provided with a reinforcing plate 18 and clamped to the body of the chamber by a ring 19 and threaded bolts '20. A stem21 passes through the diaphragm, late 18 and held thereto so as to move therewith by nuts 21 and 22 and washer 23. On the upper end of stem 21 there is mount- .ed a cross-beam 24 which may secured to the stem by nuts 25 and 26 The outer ends of cross-beam '24 are connected by rods 26a with the outer ends of a cross-beam 27 mounted on the upper end of stem 11 of diaphragm 4 and seated upon the nut 8 of that stem, and thus the movement of one diaphragm will be transmitted to the other.

Gasoline from a suitable source of supply passes through a pipe 28 to a nipple 29 having a suitable check-valve 30 and thence into the pump chamber 2 from whence it passes through a nipple 31 having a suitable checkvalve 32 into a T-coupling 33 from one branch of which a pipe or conduit 34 will lead to a carburetor (not shown) and discharged therein through a restricted aperture; and an expansion tank 35 will connect with the other branch of the T-coupling as indicated in Figure 1 of the drawings so that air will be trapped in the expansion tank to supply air pressure to the line. of fuel during the intervals of pulsations of the pulsating diaphragm of the pumping chamber. The expansion tank is expansible and collapsible in character. It is preferably of the type formed usually of light or thin metal, having circumferential holllow or tubular ribs or beads 36 so as to form a bellows-like collapsible and expansible tank or chamber in which air is trapped. It may however be any suitable form or material which will form an expansion chamber or tank.

Within the motor chamber 1 is an arm 37 preferably formed of two substantially parallel bars 38 spaced from each other, hinged at one end, for instance by a cotter pin pivot 39 to a bracket 40 so as to swing and provided at its free end witha valve 41 at the lower end of a stem 42 flattened in cross section and pivoted b a cotter pin 43 so as to swing from the end 0 the arm 37 and designed to control the discharge of oil from the chamber through an exhaust port 44 which opens into a bore 45 formed in the base of the chamber as shown in Figure 3, through which oil exhausted from the chamber passes to a nipple 46 from which a pipe 47 leads to the crank-case (not shown). The arm37 has also pivotally supported from 1t adjacent to its free end, a valve '48 to control the 011 1 nlet port 49, through which oil is delivered into the motor chamber as'it is pumped thereto through the oil line pipe;3 connected by a nip ple 50 to a bore 51 in the base of. the motor chamber so that the pressure of the oil thus supplied may actuate the diaphragm of the chamber for transmitting movement to the flexible diaphragm 17 of the liquid fuel pumpin chamber so as to pump the liquid fuel in t e form of gasoline from that chamber onward to the carburetor as before indicated. v

The valve carrying arm 37 is provided with a slidable shaft 52 carrying a roller 53 positioned in the path of movement of the cam .slots 54 formed in the bars 38 of arm 37, and

spiral springs 55 connected at one end to shaft 52 and at the other end to a shaft 56 mounted in bearings 57 formed inthe free ends of bars 38 serve to hold the roller 53 in rolling and yielding contact with the periphery of cam 13. When the diaphragms 4 and 17 of the respective chambers 1 and 2 are in normal lowered position the roller 53 is in contact with the upper inclined face of cam 13 and the oil inlet valve 48 is open for admission of oil from the oil pump line and the exhaust valve 44 is closed to prevent escape of oil from chamber 1, as indicated in Figure 3 of the drawings. As oil accumulates in chamber 1 it presses against the diaphragm 4 and lifts the latter so that the yoke formed by the cross beams 27 and 24 and connecting rods 26a is raised so as to lift the diaphragm 17 of the liquid fuel pump chamber 2 to substantially the same extent as the diaphragm of motor chamber into position for the following expelling stroke of the diaphragm piston 17. During the upward stroke of diaphragm 4 a the stem 11 is carried with itand the enlarged end or head of the stem is brought into contact with the base of the cam 13 and lifts the cam and the roller 53 is pressed rearwardly by contact with the uper inclined face of the cam against the influence of the springs 55 until the apex of the cam is reached Whereupon the retracting influence of the springs will cause the roller 53 to be snapped over the apex of the cam and into contact with the lower inclined face of the cam vith the result that the free end of arm 37 is lowered and the oil inlet .valve 48 seated so as to close the inlet port while at the same time the exhaust valve 41 is unseated so as to permit oil in chamber 1 to exhaust through the exhaust 44 around the valve stem and thence through pipe 47 to the crank-case. Contact of roller 53 with the lower inclined face of cam 13 holds valves 48 and 41 in the positions indicated in Figure 5 of the drawings until the exhaust of oil from the motor chamber 1 permits the piston diaphragm 4 to be lowered. During the downward movement of diaphragm 4 the stem 11 is lowered and when collar 9 comes in contact with the upper part of cam 13 and presses the cam downward on the stem and presses the lower inclined face of the cam against the roller 53 the roller is forced backward against the tension of springs 55 until the roller snaps across the apex of the cam and the inlet and exhaust valves shifted respectively to open and closed positions as indicated in Figure 3 of the drawings, in which positions they are held by roller 53 resting on the top inclined face of the cam until the diaphragm and cam are again moved to close the inlet and open the exhaust ports of the motor chamber. The upward movement of the cam 13 and diaphragm 4 is other suitable means.

limited by a lip 58 carried by stem 11 and a stop 59 that may be suitably secured, say to the bottom of chamber 1 as illustrated in Figure 5 of the drawings.

A spring, by preference a coiled or helical spring, 60, is positioned to exert a downward pressure on the diaphragm 4 of the motor chamber'l. As illustrated it is positioned between the two chambers 1 and 2 with its upper portion bearing against the underface of the bottom to chamber 2 and its lower portion seated on the cross-beam 27 and preferably encircling the projecting upper end of the stem 11. This spring is placed under compression in the upward movement of the diaphragm 4 by pressure of oil in chamber 1, and when pressure within the chamber is lowered the recoil or expansion of the spring will exert a downward pressure on the diaphragm through cross-beam 27 and its associated parts and also exert a downward pull on the diaphragm piston 17 of the fuel feed chamber 2 and associated parts so to expel the liquid fuel from chamber 2 and discharge it under pressure through the conduit which leads the fuel to the carburetor of the motor (not shown). It thus appears that the oil in motor chamber 1 lifts the diaphragm of that chamber so as to lift the diaphragm piston of the pumping chamber 2 andby the suction or vacuum thus produced in chamber 2 cause the fuel gasoline to be drawn into the chamber 2 from which it is expelled under compression by depression of the diaphragm piston under expansion of spring 60 upon the return stroke of the diaphragm, the pulsation of diaphragm 17 for inducing an inflow of liquid fuel into the pumping chamber being effected under pressure derived from the lubricating oil pump feed line and expulsion of the liquid fuel fromthe pumping chamber being effected in the return stroke of the diaphragm piston under reduction of oil line pressure inthe motor, chamber supplemented by mechanical spring pressure on the diaphragm of the chamber.

Any reducing of pressure in the fuel line arising at the moment or time of change in the strokes of the diaphragm pistonis taken care of by the air trapped in the expansion chamber of the supply line of the liquid fuel, as before mentioned.

The shaft 52 may be help} against longitudinal movement by a U- aped pin 61 as illustrated in Figure 4; of the drawings, or by The motor and fuel feed pump may be primed for operation by manipulation of the 'diaphragms of the two chambers through the instrumentality of the yoke which connects the two diaphragms and which can be hand operated in the priming operation. y

It will be observed from the foregoing that the fuel for the engineis supplied under pressure so that a more constant and positive feed of the fuel is obtained; that the feed of the fuel is effected by a fluid pressure operated pump in which the fuel from a source of supply in induced or drawn into the pump chamber under a suction or vacuum created by movement of the pump dia )hragm piston in one direction and expelled rom the pump chamber by movement of the diaphragm piston is the opposite direction; that the pump diaphragm piston on its suction stroke is actuated under a fluid pressure created in a motor chamber into which the actuating fluid is admitted and from which it is exhausted, in alternation; that the fluid for actuating the motor which actuates the pump for feeding liquid fuel to the engine is obtained from the oil line of the lubricating system of an automobile, air-plane or other motor driven body, and that if there be a failure in the oil line the engine will stop as then no fuel will be fed to the engine and thus an element or factor of safety is provided.

It will be further observed thatthe operating motor and also the fluid pressure operat ed pump for feeding the liquid fuel to the engine requires no stuffing boxes or packings and thus is effected a saving in the cost of production and also increased efliciency in operation.

While I have provided for utilizing the oil of a lubricating system as the fluid for operating the motor which will actuate the pump which supplies liquid fuel under pressure to the engine, as the preferred embodiment of the invention, yet if any other liquid, air, gas, vacuum or agent or means be employed for operating the motor of the pump, the same would be comprised within the scope of the invention as sought to be defined by the appended claims, provided that other features of the invention be employed in connection therewith.

. I have illustrated and described with particularity the preferred details of the various parts of the device but changes may be made therein without departing from essential features of the invention.

Having described my invention and set I forth its merits What I claim is 1. A fluid pressure fuel-feed for internal combustion engines, comprising a pump chamber and a motor chamber each provided with a flexible diaphragm piston connected one with the other, the pump chamber being in communication with a source of'liquid fuel supply and with a point of discharge, and the motor chamber included in an oil line of a lubricating system, means for supplying a mobile agent within the motor chamber from the oil line lubricating system to actuate its diaphgram piston to transmit pressure of the mobile agent to the diaphragm piston of the pump chamber to create a vacuum in the pump chamber for supplying liquid fuel to the chamber from which it is expelled to the point of discharge under pressure in the return stroke of the piston.

2. A fluid pressure fuel-feed for internal combustion engines comprising a pump chamber and a motor chamber each provided with a flexible diaphragm piston connected one with the other, the pump chamber being in communication with a source of liquidfuel supply and with a point of discharge, and the motor chamber included in an oil line of a lubricating system, means leading from an oil'line for supplying the oil to the motorchamber for actuating the motor chamber diaphragm piston for transmitting pressure from the oil to the diaphragm piston of the pump chamber to induce a flow of liquid fuel into the pump chamber from which it is expelled to the point of discharge under pressure in the return stroke of the piston and wherein upon failure in the oil line the supply of fuel to the engine is automatically indicated.

3. A fluid fuel-feed for internal combustion engines, comprising a pump chamber and a motor chamber each provided with a flexible diaphragm piston connected one with the other, the pump chamber being in communication with a source of liquid fuel supply and with a point of discharge, and the motor chamber included in an oil line to alubricating system, means for supplying a mobile agent within the motor chamber to actuate its diaphragm piston to transmit pressure of the mobile agent to the diaphragm piston of the pump chamber to induce a flow of liquid fuel into the pump chamber from which it is expelled to the point of discharge under pressure in the return stroke of the piston, and an inlet valve and an exhaust valve for controlling in alternation the inflow and exhaust of the mobile agent into and from the motor chamber the mobile agent being derived from the oil line of a lubricating system.

4. A fluid pressure fuel feed for internal combustion engines comprising a pump chamber and a motor chambereach providedwith a flexible diaphragm piston connected one with the other, the pump chamber being in communication with a source of liquid fuel supply and with a point of discharge, means for supplying a mobile agent within the motor chamber to actuate its diaphragm piston to transmit pressure of the mobile agent to the diaphragm piston of the pump chamber to induce a flow of liquid fuel into the pump chamber from which it is expelled to the point of discharge under pressure in the return stroke of the piston, a rocking arm within the motor chamber carrying an inlet valve and an exhaust valve for controlling in alternation the inflow and exhaust of the mobile agent into and from the motor chamber, and a cam operable from the diaphragm piston of the motor chamber for openlng the inlet valve and closing the exhaust valve in movement of the diaphragm piston in one direction and closing the inlet valve and opening the exhaust valve in movement of the diaphragm piston in an opposite direction.

5. In a fluid-pressure fuel-feed for internal combustion engines, comprising a liquid fuel pump chamber and a mobile agent motor chamber, each chamber provided with a flexible diaphragm, one operatively connected with the other, a rocking arm within the motor chamber carrying an inlet valve and exhaust valve for the chamber, a doublefaced cam operatively connected with the diaphragm of the motor chamber, a slidable spring influenced roller mounted in the path of movement of said cam, the cam in one movement of the diaphragm shifting the rocking arm to open the mobile agent inlet valve and close the exhaust valve and in a reverse movement acting to close the inlet valve and open the exhaust valve.

6. A fluid pressure fuel feed for internal combustion engines, comprising a liquid fuel pump chamber and a mobile agent motor chamber each provided with a flexible diaphragm, one connected with the other for joint coaction, an inlet valve and an exhaust valve, operatively connected with the diaphragm of the motor chamber for controlling admission and exhaust of the mobile agent to and from the motor chamher, the diaphragms of the motor chamber and pump chamber being moved in one direction upon admission of the mobile agent to the motor chamber, and a compression spring disposed for compression on dilation of the motor chamber diaphragm by the mobile agent and for expansion to restore the diaphragms of the motor and pump chambers to normal position in exhaust of the mobile agent from the motor chamber the motor chamber being included in an oil line of a lubricating system, and failure in the oil line serving to automatically indicate the interruption of fuel to the engine.

In testimony wherof I aflix my signature.

JOSEPH C. SNODGRASS.

Ill. 

